Process of manufacturing alloy steels in electric furnaces



Patented July 15, 1924.

STATES- PATENT OFFICE.

' NAPOLEON IETINOT, OF NEW YORK, N. Y., ASSIGNOR TO UNITED STATES FERRO-ALLOY CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF YO'RK.

. PROCESS OF MAN 'UFLOTURIN ALLOY STEELSIN ELECTRIC FURNACES.

No Drawing.

To all whom it may concem:

Be it known that I, NAPOLEON PETINOT, a citizen of the United States of America, and a residentof the city, county, and State of New York, have invented a certain new and useful Process of Manufacturing Alloy Steels in Electric Furnaces, of which the following is a full, clear, and exact description. This invention relates in general to the productionof alloy steels in electric furnaces, and more particularly to low carbon alloy steels such as chromium, tungsten, manganese, vanadium, and other alloy steels '1 having a low carbon content. In carrying out my process,,I employ an electric furnace. It has heretofore been a practice ofthe art in making low carbon alloy steels in electric furnaces to first make a plain carbon steel lowenough in sulphur and phosphorus to comply with the specifications for such elements, and then to add enough of the ferro-alloy to bring up the content ofthe steel bath, as regards the alloying element, to the desired percentage. Since all ferroalloys contain more or less carbon this carbon will be takenup by the molten steel. For this reason, therefore, it has been necessary to make allowance for, the carbon, and

- when a low carbon alloy steel was required,

it was exceedingly difiicult and in some cases impossible to produce the alloy steel with the desired low carbon content; In any such case, a very low carbon ferro-alloy must be used, and this practice is expensive since such fer'ro-alloys are costly.

By using my invention, allo steels of low carbon content (for example rom 0.05% of carbon and upwards) can be made without 40 using low carbon ferro-alloys for the purpose ofrintroducing the alloying substance. Some of the objects of my invention have been to simplify the present methods of the art in the production of low carbon'ferroalloys; to reduce the cost of manufacture of such alloys; to do away with using low carbon. ferro-alloys for introducing the alloying substance; and to do awa with the .use of .50 acting as a reducer.

, In carrying out my invention, I make a bath of iron with a ow carbon content in burnt lime for the formation of the carbide an electric furnace of the arc type and preferably in a basic lined furnace of such type. 5 This is easily accomplished by melting cold Application filed'November 16, 1922. Serial No. 601,407.

scrap in the furnace, or transferring hot metal into the furnace from a basic open steel has been formed in the electric furnace as above described, and the first sl ag removed, I then add chrome ore in a ground form. The following analysis is a typical one of such chrome ore:

Per cent. Sesquioxide ofchrome 48 to 56 Silica 1 to 2 Alumina 7 to 15 Magnesiaflnll 13 to 16 Iron oxide 14 After such ground chrome ore has been added, the current is again applied to the furnace, sufiicient in quantity to melt the contents, and thereby achrome .slag is formed. The slag is then carburized by an addition'of some carbonaceous-matter such as coke dust, petroleum coke, anthracite coal, carbon electrodes or thelike. There is then 35 immediately formed carbides of lime aluminum, magnesium, etc., and the oxide of chromium and iron will be reduced to their metallic form, and will be absorbed by the bathfof steel.

If a tungsten steel were desired, there would be used in place of the chrome ore the calcium salt of tungsten, known as schelite. This schelite having been ground would be added to the bath of steel, and then after. the first slag was removed, the slag is car-' burized as above set forth.- The result in this case would be that the tungsten formed wofild be absorbed by the steel, leaving a slag of carbides in which the element, 091- cium, would predominate.

From the foregoing description, t Will.

be plainly seen and-understood that my process, as herein described, is' readlly apphcable to the production of other alloys such as vanadium, manganese, and the like, and

that the production of such other steels will be attended by as advantageous results as those which follow from the production of chrome and tungsten steels, as herein 11o more specifically described. In other words, it will be clear to anyone skilled in metallurgy how my invention can be applied in the production of any alloy steels of low carbon content.

Having thus described my invention what I claim is:

' bath of? steel, then removing thev first slag,

then the formation ofa slag with the impure ore of the metal to be reduced, and then carburizing the metallic slag thus produced.

p 3. Aprocess of makingalloy steels inelec tric furnaces comprising the formation of a bath of iron, having a low carbon content, 1 in a basic lined furnace of the arc type, then forming a slag with the impure oreof the metal to be reduced, and then carburizing such metallic slag. I

4. A process of making alloy steels in elec-1 tric "furnaces comprising the formation of a bath of iron having a low carbon content, then removing the first slag, then forming a slag with the impure ore of the metal to be reduced, and then adding a layer of carbonaceous material in powder form, whereby the metallic slag is carburized.

5. A process of making alloy steels in electric furnaces comprising the formation of a bath of iron having a low carbon content in an electric furnace, then removing the first slag produced, then adding chrome ore in a ground form, and then forming a chrome slag. v

'6. A process of making alloy steels in electric furnaces comprising the formation of a bath of iron having a low carbon content in an electric furnace, then removing the first slag produced, then adding chrome ore in a ground form, then forming achrome slag,

and then carburizing the chrome slag by adding a vlayer of carbonaceous material thereto, I

In testimony whereof, I have hereunto signed my name.

NAPOLEON PETINOT. 

